Vanthali, Junagarh District, Gujarat
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Draft Report क� द्र�यभू�म �ल बो जल संसाधन, नद� �वकास और गंगा संर�ण मंत्रा भारत सरकार Central Ground Water Board Ministry of Water Resources, River Development and Ganga Rejuvenation Government of India Report on AQUIFER MAPS AND MANAGEMENT PLAN Vanthali, Junagarh District, Gujarat पि�चमी म鵍ा �ेत, अहमदाबाद West Central Region, Ahmedabad भारत सरकार जल संसाधन, नदी िवकास एवम् गंगा संरक् मं�ालय क��ीय भूिम जल बोडर GOVERNMENT OF INDIA MINISTRY OF WATER RESOURCES, RIVER DEVELOPMENT AND GANGA REJUVENATION REPORT ON AQUIFER MAPS & MANAGEMENT PLANS VANTHALI TALUKA, JUNAGADH DISTRICT, GUJARAT STATE CENTRAL GROUND WATER BOARD WEST CENTRAL REGION AHMEDABAD REPORT ON AQUIFER MAPS & MANAGEMENT PLANS VANTHALI TALUKA, JUNAGADH DISTRICT, GUJARAT STATE 1. SALIENT FEATURES 1 Name of the Vanthali - 357.51 Km2 TALUKA& Area, 21°21’00” to 21°34’38” N Location(Fig-1) 70°11’26” to 70°27’23” E 2 No. of Town, villages 1, 46 3 District/State Junagadh/Gujarat 4 Population (2011 Male- 43013, Female- 39622, Total- 82,635 Census) 5 Normal Rainfall (mm) 865.00 mm- Monsoon Rainfall (IMD) (in mm) (Long Term) 50 1052.50 mm -Average Monsoon Rainfall (in mm) (2003-12) 6 Agriculture (20015-16) Kharif Crops Rabi Crops Crop Area in Hact Crop Area in Hact Groundnut 14000 Wheat 1250 Tal 50 Juvar 0 Castor 50 Castor 0 Gram 10 Bajri 20 Bajri 0 Tuver 40 Tuver 0 Mug 50 Mug 0 Udad 50 Mustered 0 Cotton 11700 Isabgol 0 Sugarcane 0 Sugarcane 0 Vegetables 300 Vegetables 150 Fodder 1050 Fodder 325 Gam Guvar 0 Jira 300 Soyabin 0 Onion 10 Coriander 5500 Garlic 10 Methi 0 Total 27310 Total 7555 7 Existing and future Sector Existing (MCM) Future water demands (MCM) (MCM) (Year 2025) Domestic and Industrial 2.95 3.95 Irrigation 55.43 25.56 8 Water level behaviour 13.51-30.25 m (Pre-monsoon) (2015)(Fig-2 & 3) AQUIFER MAPS & MANAGEMENT PLANS VANTHALI TALUKA, JUNAGADHDISTRICT, GUJARAT STATE 267 Fig-1: Location Map 1. Hydrogeology: Main aquifer in the areais basaltic aquifer (Fig. 2) where the ground water exists upto the depth of weathering and in the fracture zones wherever encountered in the depth. Two hydrogeological Cross sections are given in Fig. 3. AQUIFER MAPS & MANAGEMENT PLANS VANTHALI TALUKA, JUNAGADHDISTRICT, GUJARAT STATE 268 Subsurface Hydrogeology As inferred from borehole data of the Vanthali Taluka, weathered and fractured Basalt forms the principal aquifer in the Taluka. Groundwater in this aquifer occurs under unconfined conditions and in the fractures encountered in the massive basaltic formation in the depth. The movement of groundwater is controlled by the extent of weathering, fracture and joints in the trap formation. Groundwater exploration has been done down to a max. depth of 200 mbgl and the discharge encountered 8 lps by compressor during drilling. 2. AQUIFER DISPOSITION Name of Aquifer Nature of Aquifer depth Nature of Compres Quality aquifer material aquifer and zone porosity sor encountered discharg (m) e Miliolitic Limestone Unconfined Negligible Primary and - - Limestone secondary (Poreses, fractures and solution cavities) Deccan Trap Basalt Unconfined 0 to 21 Secondary ( 1 to 2 lps Fresh (Weathered weathered & and fractured) fracture) Deep Fracture Explore up to the Secondary Compress EC 4900 (Massive & depth of 200 m, (fractures, joints, or µS/cm amygdolidal) zone shears and flow discharge encountered at contacts ) 8 LPS 50 & 109m AQUIFER MAPS & MANAGEMENT PLANS VANTHALI TALUKA, JUNAGADHDISTRICT, GUJARAT STATE 269 Fig 2: Aquifer disposition of the area AQUIFER MAPS & MANAGEMENT PLANS VANTHALI TALUKA, JUNAGADHDISTRICT, GUJARAT STATE 270 Fig-3: Stratigraphic Section Depth to water level: Large part of the taluka is having depth to water level mostly between 10 to 40 m bgl (Fig.4). Decadal average water level mostly between the period of May 2006 and 2015 ranges from 8.05 to 23.71m bgl. (Fig5). The decadal average depth to water levels also depict almost similar picture to the DTWL May 2015. Long term groundwater fluctuation of water level for pre-monsoon and post- monsoon period are depicted in Fig. 6 & 7 for the period of 1987 to 2015. Ranges of the long-term fluctuation is given in Table below. Pre-monsoon(1987-2015) Post-monsoon(1987-2015) Rise Fall Rise Fall Min Max Min Max Min Max Min Max 0 4 0.2 4 4.90 7.00 Negligible AQUIFER MAPS & MANAGEMENT PLANS VANTHALI TALUKA, JUNAGADHDISTRICT, GUJARAT STATE 271 Fig 4: DTW Map (Pre monsoon) Fig 5: Decadal Average Depth to Water Level Fig.6 Absolute fluctuation Pre-monsoon Fig. 7 Absolute fluctuation Post-monsoon Water Table map (Fig 8) shows water table in general are ranges from ground level to 50 m above msl and groundwater flow direction is from NE to SW. A groundwater mount is shown in the South-Eastern side of the Taluka. AQUIFER MAPS & MANAGEMENT PLANS VANTHALI TALUKA, JUNAGADHDISTRICT, GUJARAT STATE 272 Fig 8: Water Table map with flow direction 3. Groundwater resource extraction, contamination. Dynamic GW Resources in MCM Total groundwater availability of the area is estimated in year 2013 is 84.94 MCM and total groundwater withdrawal for all purposes is 58.38 MCM. The stage of groundwater development is 68.73% and the taluka is categorized “Safe” (Table 2). Table: 2 Groundwater resources 2013 S No. Item Fresh Saline 1 Area 393.20 - 2 Total GW Recharge (MCM) 89.41 - 3 Net GW Availability (MCM) 84.94 - 4 Gross Draft (MCM) 58.38 - 5 Net Availability for Future 25.56 - Irrigation (MCM) 6 Stage of GW Development % 68.73 (safe) - AQUIFER MAPS & MANAGEMENT PLANS VANTHALI TALUKA, JUNAGADHDISTRICT, GUJARAT STATE 273 In Storage GW Resources Fracture Fracture - Fraction Rock Areas/Depth Rock Areas/Depth Typr of Rock Formation of Rock Typr km) Area (sq Unit Total km) (sq Area Fresh km) Area (sq Saline/Brackish Depth of Bedrock(Soft upto which the aquifercommonly is (m) Areas) (HR Developed (m) in Level Water monsoon Pre Average m Total Thickness saturated Thickness of the Granular Zone below Zone zone/Productive Premonsoon WL(M) (Sy) Yield Specific Average (MCM) Resources GW storage In FRESH GW storage In BRACKISH/SALINE (MCM) Resources Basalt Weathered 388.63 374.211 14.42 18.43 13.59 4.84 0.02 36.22 1.40 Basalt-Massive- Fractured zone 374.211 14.42 12.68 0.01 47.45 1.83 Milliolitic Limestone 4.01 4.01 0 21.79 14.96 6.83 0.1 2.74 0.00 Total 392.64 378.22 14.42 86.41 3.22 Chemical quality of groundwater Groundwater quality in general is good. Salinity is expressed in terms of total dissolved solids (TDS). Most of the area in the taluka (Fig. 9 ) falls TDS < 2000 mg/litre whereas SW corner the map exhibit TDS ranges 2000 to more than 4500 mg/l. Min. &Max. ranges of some of the constituents is given in the following Table. Taluka Total dissolved solids Cl F HCO3 Min Max Min Max Min Max Min Max Vanthali 470 4510 128 2240 0.07 1.7 179 915 AQUIFER MAPS & MANAGEMENT PLANS VANTHALI TALUKA, JUNAGADHDISTRICT, GUJARAT STATE 274 Fig.9 Iso-TDS May 2015 Fig. 10 Iso-Chloride May 2015 Ground Water Issues • Salinity Ingress • Inherent Salinity of Gaj Formation • Sustainability of hard rock Aquifers • Non Availability of sufficient Surface Water for Irrigation. • Lack of awareness and involvement of stake holders in decision making. 4. Groundwater resource enhancement. Table-3Computation of volume (MCM) of water required for recharge Aquifer Volume of Specific yield Volume of water Volume of rain unsaturated zone factor required for water planned avilable for recharge MCM for Artificial artificial recharge recharge (MCM) Basalt 440.70 0.02 8.81 0.97 Milliolitic 12.11 0.1 1.21 0.11 Limestone Total 452.81 1.09 AQUIFER MAPS & MANAGEMENT PLANS VANTHALI TALUKA, JUNAGADHDISTRICT, GUJARAT STATE 275 Table: 4 Computation of Recharge structures. Aquifer Area feasible Volume Volume of Volume No of No of for artificial of rain water of water Farm Check recharge Sq. water planned for planned Pond Dam Km planned conservation for (Unit (Unit for through recharge storage 0.05 Artificial Farm Pond through 0.05MCM) MCM) recharge Check (MCM) Dam Basalt 131.61 3.74 2.77 0.97 55 19 Milliolitic Limestone 4.04 0.11 0.00 0.11 0 2 Total 135.64 3.85 2.77 1.09 55 21 Financial Outlay of the Plan The total estimated cost of the Plan is 767 lakh, which includes Rs 168 lakh for ground water recharge activities, Rs 550 lakh (Farm ponds), 12.60 lakh for ground water monitoring (Piezometer construction) and Rs 36.53 lakh towards operation and maintenance charges. The tentative cost estimates of the various activities of the Plan are shown in Table 5. AQUIFER MAPS & MANAGEMENT PLANS VANTHALI TALUKA, JUNAGADHDISTRICT, GUJARAT STATE 276 Table: 5 Cost estimates of Recharge structures and monitoring well (Piezometers): Feasible Tentative Quantity Rainwater Tentative Total Expected Artificial Design (in nos. harvested unit cost tentative Annual GW Recharge & or area (mcm ) (in Rs cost (in recharge/ Water in sq. m) lakh) Rs lakh) conservation Conservation (mcm) structures/ activities Recharge Structures/ Activities Check Dam 21 1.05 8 168 0.95 Sub total 168 0.95 Water Conservation Activities ( 30 m x 30m x 1.5 Farm Pond (3 m) 55 2.75 10 550 1.925 fillings) 900 sq.m or 0.1 ha Impact assessment & Monitoring Up to 80 Piezometer 21 0.6 12.6 m bgl Impact assessment will be carried out by implemneting agency O & M - 5% of total cost of the scheme 36.53 TOTAL 767.13 Note: Type, number and cost of structure may vary according to site after ground verification The tentative location of villages for construction of Check Dams and their cost estimates are shown in Fig.